Telegraph system.



HITCHCOK. TELEGRAPH SYSTEM.

APPLICATION FILED JUNE 16. 1915.

1 ,Q%,64@ Patented May 1, 1917.

2 SHEETS-SHEET I.

W awuewfoz %43 SHOT/14c 13 5 MW w w R. HITCHCOCK. TELEGRAPH SYSTEM.

APPLICATION FILED JUNE 16. 1915- Patented May 1, 1917.

2 SHEETS-SHEET 2 %13 SRO 01442136 M my vl/l lV/a L l\ W a F 5 /H m-W Z w BOMYN HITCHCOCK, OF NEW YORK, N. Y.

rnnnensrn SYSTEM.

Specification of Letters Patent.

' Patented May a, rear.

Application filed June 16, 1 .915. Serial No. 34,357.

To all whom it may concern:

Be it known that I, ROMYN Hrrcncock, a citizen of the United States, residing at New York, in the county and State-of New York, have invented certain new and useful Improvements in Telegraph Systems, of which the following is a full, clear, and exact description.

The invention which is made the subject of this application for Letters Patent resides in anelectrical system for the transmission of current impulses differentiated from each other by the intervals with reference to a given operation or initial impulse at which they are sent, and the reception of such impulses at corresponding intervals whereby each impulse is caused to efiect a result peculiar to itself. The invention involves a telegraph system of special design, with transmitting and re-- ceiving devices moving at uniform and constant speed, which speed is established and controlled locally and independently of line impulses, and comprises transmitting devices in the general nature of sunflower disks, and receiving devices of corresponding character adapted to be operatively connected at intervals to driving devices moving at substantially the same speed as those of the transmitter, and may be used for many purposes, among which a typical use is for the operation of printing telegraph instruments. I have, therefore, for purposes of illustration, confined the explanation of the means employed to systems of thischara'cter.

The distinctive feature of this invention is the complete disconnection of the synchronously moving parts from line control and the regulation of rate of speed at all stations by local pendulums all having the same period of vibration, preferably a half second of mean solar time, whereby the speed of rotation is not only constant, but an exactly known rate. "The rate being universally known, it can be established for all stations, however remotely separated, without telegraphic signaling for testing or verification.

In carryingv out my invention I employ at the .transmitting and receiving stations, rotary or equivalent contact carriers, having series of conductlng pomts or segments angularly displaced in corresponding position, and a series of contact brushes or strips adapted to bear thereon -and locally operated or controlled means for maintaining the speed of rotation of such carriers substantially constant and uniform. Each of these devices or sets of instrumentalities is adapted to be started in movement by an initial impulse, which connects them with driving mechanism adapted to rotate in exact unison, that is to say, at substantially the same absolute speed, so that corresponding contact segments will be connected to line at the same instant of time at the sending and any number of receiving stations. By connecting, therefore, the contacts of the transmitter with appropriate keys or other means for producing an impulse and transmitting it through them and the corresponding receiving contacts with different type operating magnets, the impulses corresponding to definite keys will be received by the appropriate magnets and perform their various and intended functions.

K The system further involves numerous details for permitting the necessary impulses to be properly transmitted and received, which will require for their understanding a specific description which will be given in connection with, and by reference to, the accompanying drawings.

These drawings illustrate in more or less conventional manner, the general plan of the circuits and mechanism employed, and show the essential parts of one sending and one receiving station for simplex operation in one direction over a line wire, but indicating complete circuits for two keys only.

Figure 1 is a general diagram of the sending instrument and accessories of such a system as above described.

Fig. 2 is a similar view of the receiving devices.

Fig. 3 iS a diagram illustrating the clutch mechanism for starting and stopping the contact carriers, and

Fig. 4 is a sectional view of a detail of the latter mechanism.

It will be understood from the description which follows that in the practical carrying out of the invention any suitable form of transmitting key board is used, and that any proper and known form of typewriter printer With a magnet or equivalent means for impressing each character is used at the receiving end.

1 shall first describe the apparatus at the transmitting end of the line and the manner of operating the same. On depressing any key K an electrical contact is made .at 1, which is of short duration and immediately follows the depression of the key. This opline 12, this contact is permanently connected with an insulated metallic segment 13, on the left hand side of a cylindrical extension 14. At the end of the contact carrier- 11, the contact strip 15, bearing on this eX- tension of cylinder 11, is normally in contact with the segment 13, and is connected to the line wire 16.

A relay magnet 17, is included in this circuit, and when an impulse is received at segment 13, from contact segment 10, the relay magnet is energized and operates a circuit closer 18, to complete a local circuit 19, including a battery 20, a magnet 21, and two local contact brushes 54, hearing on insulated contact rings on the shaft of the contact carrier or cylinder.

The'result of closing this circuit is to I send an impulse from the brushes 54 into and through an electric clutch of any suitable construction which connects the contact carrier with a rotating motor 23, and at the same time trips a catch 22, and releases the carrier by the mechanism illustrated more in detail in Fig. 3.

Any ordinary or well known devices may be employed for this purpose. In the present case the carrier or cylinder 11 is operatively connected with the motor 23, by some form of gearing which permits the motor to rotate unimpeded while the carrier is at rest, but when released by this magnet 21, pulling latch lever 22 out of engagement with a stop on the carrier it immediately starts in rotation under the action of the clutch, and moves with the driving device at a predetermined rate of speed which continues as long as the special conditions of the constructions adapted will permit. In other words, the transmission of series of impulses designed to print letters, or per form any other operation in the receiving machine,'is preceded by an impulse of the character above described that will unlockmagma the cylinder and permit it to make any desired number of revolutions before being stopped. For example, in Fig. 3 the shaft of the cylinder 11. is provided with a pinion 62, engaging with a gear wheel 24 on a conducting disk 25. Two brushes or contacts bear upon this disk, one 26 on its face, and the other 27 on its periphery. The magnet 21 in this case has two windings, through one of which, 28, passes the currentfrom the battery 20 to draw down the latch lever 22.

lVhen the latch lever 22 is thus brought into contact with a stop 29 it completes the circuit from the battery 30 through the second winding 31, the lever 22, the brush 27, the disk 25, the brush 26 and the clutch contact brushes 54 and-the wire 33 back to battery 30. This holds the lever 22 down until the brush 26, passing over an insulated segment 3-1 in the disk 25, breaks the circuit alnrll causes the latch 22vto again arrest the c is v The relative proportions of the pinion 62 and the gear 2t determine the number of revolutions which the cylinder 11 will make after having been once connected with the driving mechanism and started and until it is again stopped by the lever 22. It will be observed that as the contact 10 is insulated from the cylinder 11, as soon as the latter is started the brush 9 becomes dead, and has no further efi'ect until it is again brought into contact with the segment 10 by the rotation of the cylinder 11.

Having now described the manner in which the cylinder or contact carrier 11 at the transmitting station is started for each group of signals, which may besufiicient in number for sending an entire despatch, it remains to explain how the working impulses are sent for printing or performing any other necessary operation in the receiver.

The impulse sent to line and immediately following the depression of any key K, energizes, as above explained, the magnet M. This magnet, by depressing the armature l, closes a contact at 35 which completes the circuit of battery 36 and energizes the magnet 37 included in this circuit. The energization of this latter magnet draws down armature 38 onto a stop 39 and thereby connects the main generator G, through wire 40, with the armature 38, and thence through stop 39 with the contact 41 of the depressed key K, the anvil of which is connected by wire 42 with one of the series of contact brushes 43 bearing on the surface of the nected with each other, angularly displaced aaaaeao and connected by insulated paths with the insulated metallic portion 45 on the right hand side of the ring or extension 14 on the cylinder 11. Upon this ring 45 bears a contact strip or brush 46 connected to line, and in the ring is an insulating segment 47 upon which the brush 46 normally bears when the cylinder is at rest.

The operation of magnet 37 just described, does not result, however, in a current passing to line, since there is normally no electrical connection between the insulated brushes 43 and the brush 46, but as soon as a contact 44 set in the surface of the cylinder comes under the particular brush 43, so connected with the key, an impulse proceeds from the generator to line through such contact. The starting impulse when sent, resulting from the depression of a key, precedes this line impulse, but as the energization of magnet M is of very brief duration, the magnet 37 is either supplied with a weak constant current to enable it to retain its armature depressed when it is once attracted, or it may do this by the effect of residual magnetism. It becomes necessary, therefore, to provide some means for retracting the armature 38 after each attraction, and this is accomplished by the magnet 48. This magnet, which is provided with a resistance shunt 49 is in the main circuit of the generator G to the armature 38, and as soon as the full current from the generator flows through this circuit, the magnet acquires sufiicient power to draw down its end of armature38 and interrupt the flow of current to line. This, however, does not occur until an impulse suflicient for the purpose intended has been transmitted to the receiving station. The number of contacts 44 and brushes 43 is one half that of the keys, as each key sends either a positive or a negative current to line. The same contact, therefore, may send current impulses to print two letters or effect two other different operations in the receiver. A detailed explanation of this feature, so far as the transmitter is concerned, is not necessary, as the parts are mere duplicates, but for purposes of illustration I have shown in Fig. 1 a positive and a negative current key connected with one strip 43, and their operation will be readily understood by an examination of the drawing without further description.

I now pass to a description of the receiving apparatus and its mode of operation as illustrated in Fig. 2, using substantially the same reference numerals to indicate parts therein which correspond in location and function to those in the sending apparatus.

The starting impulse sent on the depression of any key reaches the receiving end of the system over the line wire 16, and passes through the brush 15 onto contact 13, upon which latter the brush normally rests, and goes to earth through contact 10 connected to contact 13, which receives the impulse, brush 9 and relay magnet 17. This impulse energizes the magnet 17, which. draws down its armature, indicated in Fig. 2 by the numeral 51, and which is connected with one pole of a battery 20, and closes the circuit through wires 52 and 53, the brushes 54, the electric clutch 65, the battery 20, and the magnet 21. This magnet releases the cylinder 11 and as'the same impulse of current has connected up the said cylinder with the driving motor 23, through the clutch 65, the cylinder makes one or more revolutions in the same. manner as the sending cylinder heretofore described. It will be observed that the only effect of the starting impulses of current is to insure that the sending and receiving cylinders are both connected with motors which revolve at substantially the same absolute speed and are started in exact phase. As soon as the cylinder starts, brush 9 leaves the contact 10 and the circuit with magnet 17 is interrupted. The main line, however, is continued to ground through the armature 51, an insulated back stop 63 and wire 64 and the coils of the polarized magnet 55, so that when the signaling impulse arrives the armature 50 of the polarized magnet is thrown to one or other of two contacts 57 or 58, and an impulse from the-battery 59 is sent in one direction or the other through a printing or other magnet60 or 61, the brush 43 and the contact 44, which at that instant are in electrical connection and back to the battery through the brush 46.

In order that any given contact 44 and brush 43 in the transmitter shall be in engagement at the precise instant of time that the corresponding contact and brush in the receiver are in engagement, a substantially absolute rate of speed must be maintained at all times in the movements of the sending and receiving cylinders 11. This condition is necessarily established for since the cylinders are always in the same phase position when at rest, and the driving mechanisms at both stations are maintained at the same speed, the transmitting and receiving cylinders are merely connected up to them in phase by the starting impulse. The speed of the driving devices must moreover be produced and controlled by means entirely independent of the line and of all transmitted impulses.

Various means for effecting synchronism have been practically applied in telegraphy, but all have required the sending of regulative or corrective line impulses, or reliance has been placed upon an unregulated approximately uniform rate of movement in such devices as sunflower distributors having a very limited number of conductive segments, started together and permitted to make but a single revolution and then step.

By the method which I propose there is a speed regulation of the driving mechanism and the speed is regulated at a definitely determined rate capable of exact mathematical expression in terms of physical constants. It is a control by the force of gravity, the value of which is accurately measurable for anylocality. The speed is governed by the swing of a pendulum at each station. If it Were practicable or desirable to use an astronomical clock under observatoryv conditions, it would be possible by this I means, at least theoretically, to maintain apparatus continuously revolving at substantially the same absolute speed at any number of stations and all that would be necessary for the operation of the system would be to connect the telegraphic apparatus with such driving means in exact phase at any number of stations by means of a starting impulse. Practically, however, a good clock movement used as a regulator is suficiently reliable to meet all commercial requirements, and for this purpose I may use any suitable device of the kind without regard to its particular form or principle of operation.

l have devised special means for this purpose, but for purposes of the present case l have illustrated-a device suitable for the purpose which consists of the following parts: A small battery 68, is connected at one pole to the revolving brush 70, on a clock mechanism which makes contact with a conducting segment 71, on a suitable disk between two insulating spaces." From the segment'7l current passes to two pairs of contact brushes 7 2 and 7 3, which bear upon a cylinder 67, on the shaft of the motor 23..

Assume that the revolving brush 70 makes one revolution every half second and that the motor shaft makes three revolutions in the same time. So long as the shaft turns at this exact speed the two pairs of brushes 72 and 7 3 will rest upon insulation at the instant of time when the brush 70 is in contact with the segment 71. lit the motor runs either fast or slow one of the two pairs of the brushes 72 or 73, will momentarily make contact with one of the conducting not necessary to explain in detail how this 7 naaaeeo may be efiected as there are various mown ways of accomplishing the result any of which may be used that will subserve the graph instruments are connected at any desired periods in exact phase and hence without regard to the line, a transmitter is always capable of operating any number of receiving instruments to print letters or perform any other operations by the transmission over the line of single impulses of current one for each letter or other operation.

It will be understood that the invention covered by this application is not limited to the specific devices which I have shown and described as used forcarrying out the system, but may include all others for performing the same functions in substantially the same manner.

' What I claim is:

1. In a telegraph system, the combination with transmitting andreceiving mechanism, of constantly running motors for imparting the proper movements thereto, clock mechanisms adjusted to run at a fixed rate, means operated by the same without affecting their rate, for maintaining the motors running at .a correspondingly uniform and exact rate independently of the action or effect of line impulses, and means for connecting the sending and receiving devices with the motors in exact phase, whereby the circuit is se lective for the particular movement desired at the instant of the transmission and receipt of such impulses.

2. In a telegraph system which depends for selective action upon apparatus at each station driven at exactly a fixed rate of speed, the combinationwith the. signal selective means of constantly running motors adapted to operate the same at the proper times, local means independent in operation of the action or eflect of line impulses,,and comprising clock mechanism adjusted to run at a fixed and definite rate, and means operated thereby and imparting no varying load thereon to affect the rate, for controlling the speed ofthe motors and maintaining the same uniform at all times,

3. In a telegraphic system having transmitting and receiving apparatus operated by driving means runnin at the same speed at each station, the combination with means for selectively determining the operations of line impulses, of a constantly running driving motor therefor, means for connecting the said apparatus with the motor and thereby starting it in operation, means for stopping the same, a clock mechanism'at each station adjusted to run at a fixed rate, and means operated by the same and imposing no load thereon that will afiect its rate, for locally controlling the speed of the motor and maintaining it uniform at all times, in- 10 dependent of the action or effect of'line impulses.

In testimony whereof I affix my signature.

ROMYN ITCHCOCK. 

